Direct manipulation allows a user to drag an object (such as an icon, a window (or panel), or text) that is displayed on a computer screen. The user can drop the object onto a target. The dropped object is known as the source object. If an action is appropriate to the act of dropping, then the target and source will somehow "affect" each other in a manner that is specified by the target or source's defaults or characteristics.
For example, suppose a user wished to print a file that is labeled "document A". Document A is represented on the computer screen by an icon. The user uses a mouse pointer to drag the document A icon towards an icon that represents a printer. When the document A icon is located on top of the printer icon, the user releases the document A icon, thereby dropping it onto the printer icon. The specific printer that is represented by the printer icon will then print document A in accordance with default parameters that are associated with the printer icon.
Suppose, however, that the user wished to change the default parameters of the print action. For example, the user may wish to specify a different printer or a different paper size. Conventional art requires changing the default parameters outside of the direct manipulation operation. The user can use a command line directive to directly change the parameters. However, direct manipulation is meant to encourage the use of Graphical User Interfaces (GUI's) in order to simplify the learning process of the interface for a user. Many users may be unfamiliar with such a command line or its proper use. Another way to change the default parameters is for the user to open the printer object. Once the printer object is opened, the user must navigate through the printer interface (such as a window) to find the default parameter settings and then change those settings. After the settings have been changed, the user then closes the printer object and drags the document object to the printer object. The document object is then dropped onto the printer object. After the drop operation has occurred, the default parameters can be restored by either using a command line or by reopening the printer object and repeating the above procedure.